Water trampoline



FIG. 1 is a perspective view of the trampoline showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan thereof, the broken lines are for illustrative purposes only and form no part of the claimed design; and,

FIG. 4 is a side elevational view thereof. 

The ornamental design for a water trampoline, as shown and described. 